Two phases of the mechanism of messenger-RNA translation are being inestigated. Specifically: 1. The conformation, and any changes in conformation that exist, in the anticodon arm of tRNAs during messenger-RNA translation is being studied by C13-NMR spectroscopy of a tRNa specifically labeled at one anticodon site with C13. 2. The nucleotide sequence about the single site of initiation of translantion of the monocistronic eucaryotic message, Satellite Tobacco Necrosis Virus-RNA is being examined in the hopes of defining features of messenger-RNA involved in initiation of translation.